21x21x1 Allergy Gold Permanent Electrostatic Filter. The combination of high arrestance and low resistance is the balance that today's high efficiency systems need. The Allergy Gold is the perfect balance of high arrestance, 90%, and low resistance at .12" w.g. The Allergy Gold utilizes a patented configuration of alternate polarity, self-charging layers of polypropylene filtration media, to attract particles as small as .1 micron. (one micron is 1/25,000 of an inch!)

90% Peak Arrestance

89% Average Arrestance

.12" Initial Resistance at 1200 CFM

85 grams Dust Holding Capacity at .5" w.g.

125 grams Dust Holding Capacity at 1" w.g

How does an electrostatic filter work?The electrostatic air filters manufactured by Dust Free utilize synthetic material which develops an electrostatic charge as friction is applied to the plastic fibers. In the filters case, air flowing through the filter provides the necessary friction. This can be demonstrated by rubbing the surface of the filter with a cloth briskly and placing the filter over light weight flakes of material such as tea leaves, or styrofoam chips. The small chips will be attracted to the filter surface and held there due to the charge that developed on the filter as a result of rubbing it. The electrostatic charge that is developed as air passes through the filter, increases the filters attraction to particles such as pollen, molds, and dust.

How does I clean my electrostatic filter?

1. Use a vacuum cleaner to remove any heavy buildup of dust and lint that may have accumulated.

2. Lay the filter flat and spray it with a cleaning detergent(409, Fantastic, Rugged Red, Ivory Liquid, etc.) on one side and then the other until the filter is soaked with the detergent. The amount of detergent required will be dependent upon the amount and type of pollutants held in the filter.

3. Lay the filter with the "wash" arrow , or dirtiest side, down or prop at angle against fence or outside wall and flush the detergent from the filter using a garden hose with a nozzle set at the high pressure setting. If laying flat, a 1" or 2" object should be placed under one side of the filter frame to allow room for the water and dirt to escape. Turn the filter over and repeat the same procedure.

4. Perform steps 2 and 3 until the filter is clean. If the filter is extremely soiled, it may be more convenient to use a car wash facility to remove all embedded dirt from the filter. Always lay the filter flat when using high pressure water for cleaning.

5. Shake excess water out of the filter and allow it to drip dry to the extent that it can be carried without dripping water.

IMPORTANT: Your filter should be cleaned regularly to maintain maximum air flow in the system.